Colorado River’s Oxygen Levels Dropping

The volunteers of Austin Youth River Watch regularly test the water in the Colorado.

Austin Youth River Watch

The Colorado River not only supplies much of Central Texas with its drinking water, it’s also a cherished destination for summer recreation seekers. But new data suggests that the health of the river ecosystem might be in jeopardy.

And authorities might not have known about the scope of the problem without the help of some teenage naturalists.

For about 20 years, Austin Youth River Watch has organized groups of teens to monitor the water quality of the Colorado. Every week they check water at different parts of the river and its tributaries. Lately they’ve been getting some unusual readings.

“We’ve been picking up low levels of oxygen over the past few weeks, and we’re pretty concerned,” said Brent Lyles, executive director of the river watch.

Lyles says the group is working with the City of Austin and the Lower Colorado River Authority to figure out why oxygen levels might be dropping. Less oxygen could spell trouble for fish and other wildlife. The river has already seen a die-off of Asian clams.

That’s happened before, Lyles said, “but this one seems to be connected to the low oxygen levels, high temperatures and low flow rates.”

Flow rates are low because the recent drought has meant less water running from creeks and streams into the Colorado. That means less oxygen.

Perhaps more importantly, the drought prompted the LCRA to stop its annual releases of water from the Highland Lakes to rice farmers downstream.

“Last year at this time there was essentially a flushing of water every day coming down the river, and this year that’s not there,” Lyles said. “So it’s changing the ecology of the river.”

Lyles says his team of teenage researchers will keep sending their data on to the city and the LCRA while scientists try to unravel the causes and effects of oxygen depletion.